Assess the effects of biventricular pacing on function capacity in a heart failure population who meet the current indications for ICD implant. Demonstrate improvement in functional capacity as measured by oxygen consumption, demonstrate improvement in patients' quality of life as measured by self-assessment, demonstrate appropriate ATP conversion measured by MVT induction and conversion testing, and assess safety measured by appropriate ventricular tachyarrhythmia detection time, incidence of severe device-related adverse events and perioperative mortality.